I have Bipolar Disorder characterized most by Manic episodes. Some are not all that bad; they're just a pain in the ass when I have something to do or someone to meet/people to be around. Anyways, I have noticed that when I can't get to sleep at night because my Seroquel doesn't seem to want to do its job, I take Melatonin, usually at 3 mgs. to start off with, then another 3 mgs., which usually knocks me out.
I have also tried Chamomile Tea with positive effects, but since I suffer from enuresis (bed-wetting), I have had to discontinue, because even if I take my medication for enuresis, I still go, which normally wouldn't happen otherwise.
That is not to say that I don't recommend Chamomile Tea. I would actually highly recommend to anybody, except if you have enuresis, even if you take medication for it.